After two years of forced hibernation, the road sector is expected to be alive and kicking, thanks to the new government, which is expected to award 4,000 km of roads to be bid via public-private partnership (PPP) mode. Road equipment is one segment that can drive the equipment demand, and given the investments planned in road projects, the demand for road equipment is set to witness an upsurge. As put it by Amit Gossain, EVP Marketing, Business Development and Corporate Affairs, JCB India, "Due to the strong pipeline of road projects to be awarded by the National Highways Authority of India (NHAI) and state governments, the opportunities for the road equipment manufacturers are sizeable."

"There is a huge moral upliftment for road builders and developers community because of the change in government and the various action plans announced by the government. So we are very much encouraged," avers DK Sen, Senior Vice President & Head Transportation Infrastructure, L&T Construction. "The market is projected to increase to 2,700 units in 2014, and grow thereafter at a CAGR of 13.62 per cent to a level of 4,500 units by 2018," says Samir Bansal, General Manager-India, Off-Highway Research. In road equipment, compactors play a vital role in the construction of high quality roads. The level of compaction during road construction is one of the most critical aspects, directly reflecting the outcome of the quality of the road being constructed. The asphalt mix design, the selection of roller/compactor with its operating weight, vibration with its characteristic variables of frequency and amplitude, the correct operation and handling of the roller/compactor, all play vital roles in the quality of the end product. Equipment India zooms in on three major areas of compaction equipment that help improve machine performance, O&M cost, and operator safety and comfort.

Maximising performance
With regard to maximising compactor performance, Equipment India looked at four parameters such as engine and hydraulics, higher steerability and curb clearance, water system performance, and greadability. Here is what the OEMs had to say and what features they offer and their advantages.

Says Girish Dixit, General Manager Engineering & Design, Wirtgen India, "Hamm soil and asphalt compactors are equipped with highly durable, fuel efficient Cummins engine and world-class hydraulics from Bosch. With the trouble-free performance of the hydraulic system, desirable performance of the engines will improve the overall performance of the machine. Hamm asphalt compactors steer very gently and smoothly in order to prevent the asphalt from buckling and shifting. These compactors have excellent drum edge visibility with sliding seat console with operator friendly features making the machine easy to operate. Inbuilt frame design to achieve higher curb clearance enables machine to go close to curb/median during compaction. This will avoid additional usage of plate compactor/walk behind compactors generally used to compact the layer close to curb."

With regards to water system performance, Dixit says, "Wirtgen models have two highly durable and high pressure water pumps, one used for the operation and other as stand-by. Three stage filtration (Filling/Inline/Nozzle) of water with plastic nozzles is provided for maintenance-free operation. He adds, "Hamm soil compactor have better climbing ability to operate in higher gradient locations. The weight distribution between front and rear of the machine is such that the gradeability is achieved both in forward and reverse movement of the machine."

According to Prantik Saha, Marketing Manager Road Construction Equipment, Atlas Copco, soil compactor Dynapac CA 255 and tandem asphalt roller dynapac CC385 from Atlas Copco are both equipped with highly fuel efficient liquid cooled Kirloskar engine. This advanced engine ensures low cost of operation and maintenance. He adds, "Both the CA 255 and the CC 385 also have the most advanced 90 series closed loop hydraulic system ensuring highest performance with least volume of hydraulic oil. Thus low maintenance cost on hydraulics. On steerability, Dynapac machines are designed to have low turning radius to ensure better manoeuvrability and hence helps the operator reach difficult corners and edges."

Highlighting specifically on the water sprinkler system feature, Saha adds, "The Dynapac CC 385 has the most advanced nozzles, which spray optimum quantity of water, sufficient enough to make the drum wet, but not enough to cool down the hot asphalt. Moreover, with only four nozzles, entire width of the drum is covered. Finally, Dynapac machines use a superior fail safe axle system, which provides highest gradeability in its class without any additional drum drive."

Says Gossain, "JCB compactors are powered by our robust, fully tropicalised, low fuel consumption JCB ecoMAX engine. JCB compactors offer tillable steering, which facilitates in highest operator comfort. The curb clearance of the mini-tandem VMT330 is highest in its category at 593 mm. We use advanced water sprinkling system. The VMT860 tandem roller is equipped with additional water pump to ensure zero breakdowns during critical asphalt compaction works. The water sprinkling system has three stage filtration to ensure lesser clogging of water jets. JCB compactors provide highest gradeability in their respective categories."

Gossain adds, "We use world-class air filters and fuel filters, which go through stringent quality checks at JCB. The reliability of the machine depends highly on the engine performance, hydraulic power, the axle and the vibration mechanisms. JCB compactors come with solid steel canopy, which makes the machine more robust and minimises the damage during any mishap."

"The four-cylinder powerful water cooled Deutz engine meets all present day emission regulations. Engines and hydraulic components can be exposed to high loads and must be totally reliable for efficient long term performance. Bomag only uses components from approved suppliers ensured by rigorous testing. A return flow filter in the hydraulic system and a high capacity fuel pre cleaner ensures high uptime," explains Blesson Varghese, Managing Director, Marini India.

Varghese adds, "Roller operators value a reliable sprinkler system and with these articulated models, Bomag has delivered reliability as never before. The automatic sprinkler system helps economically meter the water quantity with an interval switch, which means fewer tank filling stops are required. Some of the features include easy accessibility of the tank from the ground and can be filled quickly and safely; provides a low centre of gravity and increase driving stability; no restricted view of the drums; due to reliable filtering dirt particles are retained in a fine-meshed net when the tank is filled. The nozzles are also equipped with a filter and the sprinkler pipes are sheltered from the wind above the drums. The driver will always see that the nozzles are functioning perfectly at the front and rear from the operator's position." Bomag offers a flexible compaction system with standard double vibratory drum with two amplitudes and two frequencies for thick base and thin layers.

Says Sanjay Wadnekar, Vice President, LiuGong India, "LiuGong compactors CLG 614 is a versatile machine built considering the needs of Indian customers for efficiency, and designed for powerful efficient soil compaction, which is used in different types of terrain. CLG 614 has trusted and proven four-cylinder, water cooled, turbocharged 125 hp engine compliant to prevailing emission norms, and dual frequency technology that improves compaction in various conditions, the high heat dispersion radiator with parallel wing design of engine hood structure. LiuGong CLG 614 compactor is 14T effective and efficient compactor for all types of soils ranging from granular to cohesive. By maintaining tight tolerances everytime, CLG 614 machine results in higher quality work. Finished grade materials can be placed more accurately and in a shorter time period, keeping the material costs to a minimum and realising better profits. The CLG 614 single drum compactor is distinctive for its heavy-duty design and ease of operation, compacting reliable even in worse condition. The machine's exterior design, operating concept and technical design made CLG 614 an established product."

Says Abhijit Gupta, Managing Director, CASE New Holland Construction Equipment," CASE in India has introduced a water cooled engine on its popular Case 752 tandem compactor at the Bauma Conexpo show. The 10.5T Case 752 vibratory compactor with water cooled engine, which results in a substantial temperature reduction, will benefit customers with the engine's longer life and lower fuel consumption. The machine layout with the new engine also provides better access to components for servicing, reducing downtime and maintenance costs."

Optimising O&M cost
Under this, we focus one of the major advancement that has happened in the compaction technology, intelligent compaction apart from design of filters and features to improve reliability of a compactor.

"Machines with intelligent compaction system are designed to achieve optimum compaction with minimum number of passes to reduce the overall operating cost," says Dixit of Wirtgen. According to him, Hamm compactors can be offered intelligent compaction systems like Hammtronic and HCQ as optional. Hammtronic is a microprocessor-controlled machine management system. This system links, monitors and controls all important machine functions and makes machine operator free for other activities. All the information that the driver needs is displayed on an operating console with an information display. By monitoring and regulating central machine functions, Hammtronic prevents operator errors and enables the operator to concentrate on optimum rolling results.

Highlighting on the advantages of HCQ system, Dixit adds, "The HCQ system ensures even compaction, helps detection of weak points and minimise the number of passes needed. There is neither over-compaction nor loosening up and conventional soil test method for load bearing capacity is not necessary." He further adds, "Advanced systems will help to improve the quality of the roads and improve the efficiency of the operator. With intelligent systems, the quality is not dependent on the operator skills but is system driven and consistently achievable."

Dixit says, "Improved design air and fuel filters are having higher life. Using these filters will increase the change/service intervals, hence reducing the O&M cost of the machines." He adds, "In Hamm machines, all the main structures are made with high tensile steel. Engine and hydraulic system are specially designed to meet our higher ambient requirements. Using these components will improve the reliability of the machines."

Says Saha of Atlas Copco, "We offer compaction analyzer with soil, asphalt compactors, widely known as intelligent compaction. This feature helps the operator to understand when the maximum compaction has been achieved in every point of the surface. It eliminates guesswork, unnecessary passes, which results in an even compacted layer, with least time and efforts."

"Further, Atlas Copco Dynapac equipment is very high on reliability. All Dynapac machines use the most advanced and reliable components ? right from the smallest electrical cables, lugs and stickers to the larger visible components. This ensures road construction equipment of the highest quality standards is produced for the Indian market," adds Saha.

According to Varghese of Bomag, the intelligent compaction systems offered by Bomag compactors use a combination of equipment to measure compaction carried out and monitor the heat of the asphalt mat while GPS tools provide location. Using this technology together allows the operator to optimise the job by prioritising work and compacting areas of asphalt that are cooling before moving to the warmer areas of the mat. This ensures that compaction can be carried out to specification before the mat cools. Most of the latest systems will document the work carried out, showing the contractor what compaction has been done and providing a digital record that can be stored and checked if required.

"With increased engineering breakthrough, we have made machines that are efficient and effective in their respective areas of work. This is clearly evident in our machines that are equipped with Ecomode machine management system. This system allows maximum efficiency for the lowest energy consumption. The result is being able to lower fuel consumption, CO2 emission, noise pollution and off course longer service life expectancy," says Varghese.

Varghese further adds, "Tangential oscillation is a special exciter system developed by Bomag using oscillating vibration technology and is suitable for low vibration compaction work on bridges, close to buildings and on thin layers. Depending on the compaction specification, vibratory compaction can be combined with oscillation, or used separately. This makes the BW 161 ADO-5 an exceptionally effective and versatile roller in the 10T class, easy to operate and requiring very little maintenance." Wadnekar says, "LiuGong India believes in continuously improving the products and has invested into its R&D capabilities for customer benefits and driven new innovations and upgrades to this machine. Among the potential benefits of IC technology, an IC roller increases the productivity, because the compaction energy is customised, based on the measured stiffness and results in the rapid increase in the compaction during the initial passes which results in fewer passes to reach the target. Other benefit of using IC technology is the better capability to compact the deeper lifts, since the maximum amplitude that is used during the roller passes is increased when compared to the conventional rollers. Fewer pass results in saving the time, fuel and machine maintenance. CLG 614 machines are built specifically for the Indian road and are among the best in compaction. Excellent maneuverability and compact design makes this machine to work in the operating demands."

Operators' safety & comfort
The efficiency and skill of an operator plays a major role in the quality of not only the end product but also on the life of the machine. The operators comfort while on the job, to a great extent, has a strong bearing on the output. So the third parameter what Equipment India looked into was on the features in-built for the safety and comfort of operators. Some of the key points were operators' platform, articulation joint, operator efficiency, reduction of noise and vibration, etc.

According to Dixit of Atlas Copco, knowledge of operator is very important in selecting high amplitude/low frequency and low amplitude/high frequency mode in the compactor. As the compaction happens from bottom to top, the initial few number of passes should be with high amplitude and when the compaction achieves certain depth, and then the remaining number of passes should be done with low amplitude. He says, "Change in the amplitude settings helps in optimising the fuel consumption and also to achieve better quality of compacted surface. Our company runs an operator training school, which is continuously engaged in providing the training for the customer operators and concerned associated with the machines."

"At JCB, our aim is to provide the most safe, most productive and most fuel efficient equipment, and our team of experts continually works towards achieving this goal. VMT 330 tandem roller is a highly versatile compactor with high compaction forces. This machine is ideal for compaction in restricted spaces as this has got high kerb clearance. JCB VM115 comes with dual anti-vibration isolation system, which reduces the vibration thus making it more comfortable for the operator to operate the machine. Sloping bonnet provides unmatched rear and all around visibility to operator. VMT 115 comes with robust, solid and functional dashboard, comfortable driver seat with arm rests. Similarly, VMT860 also offers unmatched operator comfort with two rotating operator seats," says Gossain.

According to Gossain, the operational efficiency is the best due to correct mix and configuration of vibration amplitude, frequency and centrifugal force. These parameters with optimum values along with highest fuel efficiency provided by EcoMAX engine?lead to highest output and operational efficiency. He adds, "Operator platform is mounted on hydraulic shock mounts leading to minimum transfer of vibrations to the operator, hence resulting in increased operator comfort. The articulation joints in all the JCB compactors are self-lubricating and hence, are completely maintenance free."

Gossain avers, "JCB engine noise levels are best in class. The overall machine noise levels are also lesser due to optimum design parameters and enclosures. Roll-Over-Protection-System (ROPS)/Falling Objects Protection Systems (FOPS) are available as an option. JCB also takes care of safety through emergency switches, safety decals, etc."

Wadnekar had this to say. LiuGong CLG 614 BSIII is ergonomically designed with a higher reliability, ease of service that ensures the operator safety. The designed machine has an improved ingress/egress for the convenience of the operator. However, the design of the machine is as important to the dynamics of compaction. Several initiatives taken by R&D to improve operator efficiency like frame size, wheel base, ratio of machine weight supported over the front drum to rear drum, drum diameter, drum width, drum mass, shock isolator and distance between the eccentric weight centre to drum axle."

Says Wadnekar, "LiuGong compactors offers features like three grade absorption rubber used for reducing vibration, ROPs cab, defrosting glass, foot hand throttle and air conditioned cabin with 360? view. Radiator at rear of cab reduces the dust and increases heat dispersion and reduces the vibration and sound level. For easy maintenance of the machine, articulation joints are fitted with sophisticated traction control system that provides excellent greadability."

Says Dixit of Wirtgen, "Hamm compactors are provided with isolated operator platform. There is no feel of vibration of the machine and this improves the stress-free operation of the machine and improves the operators' efficiency." He adds, "Hamm soil compactors are built with patented design of three point pendulum articulated joint. The three point articulation joint connects the front and rear ends of the compactor and enables excellent directional stability and steerability and provides driver safety on difficult terrains and for the driver's comfort. Operator safety and maintenance related features are in built design in Hamm compactors which include safety indication and alarms for any faulty conditions."

"In Hamm machine engine compartment is closed with FRP hood, which will reduce the noise levels by approximately 10-12 db. We can also provide the isolation foam as an option to reduce the noise levels further," says Dixit. According to him, ROPS/FOPS requirement is currently not mandatory as per Indian regulations, however these can be offered with the machines as option.

According to Saha, Dynapac CA 255 and Dynapac CC385 are designed to provide maximum safety to the operator with the fantastic two stage anti-vibration pad fitted below the operator platform ensuring least vibration effect to the operator. This results in better efficiency from the operator. Articulation joint is another great feature in Dynapac equipment. It is too rigid, robust and yet maintenance free. It is strong enough to absorb the uneven bounce of the drum. Saha adds, "On the reduction of noise levels, Dynapac machines produce the least noise levels as we maintain European safety norms on decibel levels. The standards are so stringently followed that our machines can be easily used even within developed metro cities, where strict norms are set for noise pollution reduction. ROPS/FOPS are offered as optional features in Dynapac machines."

Says Varghese of Bomag, "As a responsible manufacturer, we always design machines that are safe for use, and wherever possible safety redundancy system to protect the machines and operators who are using them. As seen in many of our product brochures, we have in place many simple and effective safety mechanisms for both the operators and machines. Some examples are ROPS, safety glass, emergency cut-off system/button, patented side view system, anti-slip control, and 1x1 m optimum visibility.

"As the purpose of the compactor is to produce vibration near the drums for compaction of soil, we are using the high quality anti-vibration mountings to restrict the vibration rest of the machine. With this arrangement, we have minimised the vibration levels. Apart from the above mountings, to keep the operator in vibration free mode, we adopt elevated operating platforms. The platforms are separated by anti vibration pads from the chassis of the machine," says Gupta of CASE. He adds, "We strongly believe that if the operator is relaxed operating machine he will provide better outputs. The operator is one of the biggest influencers on production, up-time, fuel burn, and machine life. We have dramatically lowered the sound levels in our equipment. This enhances operator comfort, which increases productivity. In CASE, based on the feedbacks received from customers, we improved operators' comfort. We introduced some modifications and changed the canopies to isolate operators from vibrations."

CASE STUDY
Project: Six laning of Pimpalgaon-Nashik-Gonde section of NH-3 from km 380.00 to km 440.00 (length ? 60.00 km) in Maharashtra to be executed as BOT (Toll) on DBFO pattern. The project falls on the road that connects the financial capital of India Mumbai to states like Uttar Pradesh, Madhya Pradesh, West Bengal and Odisha among others. The scope of this project includes a 6.1 km long elevated corridor by-passing the thickly populated Nashik town. The SPV has designed, engineered, funded, and constructed the project highway and is responsible for toll collection, operations and maintenance of the stretch for the period of concession.

Equipment used
Soil compactor - Wirtgen HAMM
Tandem roller - Escorts, HAMM
PTR ? Wirtgen HAMM

Reasons for selection: Since the equipments are most fuel efficient fuel saving is high. Also achieves required compaction with minimum passes to save time.

Equipment performance: All brands used are reliable as well as proven. Also these equipment are having the highest output and gradeability, and are most fuel efficient in its class.

Techno-commercial benefits: As OEMs entered into annual maintenance contract (AMC) with us, downtime of the equipment was very less and maintenance cost is also very low. With the help of AMC, we ensure the smooth running of our projects.

Challenges: As the project constructed from two-lane to six-lane, carriage width was about 13 m and quantum of work to be done in very short period was too high and had challenge to have uniform compaction across the full width. Trained and skilled manpower to run such high-end machines was a challenge.

CASE STUDY
Project: Construction of flyover and ROB at Nashik Junction on Old Mumbai Pune highway (NH-4) including bridge on river Pawana.

Executed by: BG Shirke Construction Technologies

Machine Used
L&T1107 soil compactor for earth work
L&T 752 tandem roller for bituminous work
Hamm PTR for final BC work

Selection parameter: These all equipment have good performance efficiency and also very easy for maintenance work.

Equipment performance: Good performance and provided good compaction as per MOST specs.

Challenges faced: The project is located on the Junction of two national highways where the traffic was the main concern. We erected heavy tower crane in these traffic area and also concreting to be done by place boom and also with stationary concrete pump.